根式沉井抗拔特性试验与数值模拟

Experimental and numerical simulation studies on the pull-out characteristics of rooted-caisson foundation

为了探究根式沉井基础中根键对提高抗拔承载力的影响,进行了根式沉井上拔试验,并结合图像处理技术获得沉井基础周围土体水平和竖向位移云图、土体颗粒移动矢量图等,同时运用ABAQUS有限元软件对试验进行数值模拟.结果表明:与普通沉井相比,根式沉井抗拔性能明显提高,在设置5,9,13层根键后,根式沉井抗拔承载力分别提高了42.9%、71.4%和85.7%;沉井周围土体位移影响区域呈"V"形发展,使根式沉井影响范围达到2.0倍沉井直径,说明根键能调动更大范围的土层发挥抗拔作用.该结果可为根式沉井基础的设计和优化提供参考.

In order to explore the influence of root bond on the uplift bearing capacity of the root caisson foundation,the root caisson uplift test is carried out,and combined with image processing technology to obtain the horizontal and vertical displacement cloud map of the soil around the caisson foundation,the soil particle movement vector etc.At the same time,the experiment is numerically simulated using ABAQUS finite element software.The results show that the pullout resistance of the root caisson is obviously improved compared with the ordinary caisson.After the 5,9 and 13 root bonds being set,the uplift capacity of the root caisson is increased by 42.9%,71.4%and 85.7%,respectively.The area affected by the displacement of the soil around the caisson has a"V"shape,which makes the root-type caisson’s influence range reach 2.0 times the diameter of the caisson,indicating that the root bond can mobilize a wider range of soil layers to exert the pull-out effect.The results of this paper provide a reference for the design and optimization of the root sinking foundation.